Method for forming a package, a package and a package blank

Abstract

The present invention relates to a method for forming a package by moulding a cardboard blank in such a manner that a margin area ( 2 ) of the blank, surrounding a middle portion ( 1 ) of the blank, is bent upwards to form side walls of the package while the middle portion forms a bottom of the package. The cardboard blank prior to moulding is provided with at least one area ( 4 ) of reduced bending stiffness being located in a transition zone ( 3 ) between the side walls and the bottom. The package is moulded from the blank so that the at least one area ( 4 ) of reduced bending stiffness is located in the bended areas between the side walls and the bottom and extend in the running direction of the bend. The invention further relates to a package and a package blank that can be used for forming said package.

The invention claimed is: 
     
       1. A method for forming a package, wherein the package is moulded from a cardboard blank, the blank having straight sides and rounded corners, the blank comprising a margin area surrounding a middle portion, wherein the margin area is bent upwards to form side walls of the package while the middle portion forms the bottom of the package, comprising prior to moulding, providing the blank with at least two discontinuous areas of reduced bending stiffness compared to a bending stiffness of the middle portion, the at least two discontinuous areas of reduced bending stiffness being located around the middle portion of the blank, wherein the at least two discontinuous areas of reduced bending stiffness are formed as elongated areas that run parallel to the straight sides of the blank and are separated by at least one corner section and wherein the at least one corner section does not have an area of reduced bending stiffness, and molding the package from the blank so that the at least two discontinuous areas of reduced bending stiffness are located in a transition zone between the side walls and the bottom, where the blank is deformed due to moulding. 
     
     
       2. The method according to  claim 1  wherein the at least two discontinuous areas of reduced bending stiffness are provided with a constant width of over 1 mm. 
     
     
       3. The method according to  claim 1 , wherein the at least two discontinuous areas of reduced bending stiffness are made in the blank by making the material of the blank thinner. 
     
     
       4. The method according to  claim 3 , wherein the at least two discontinuous areas of reduced bending stiffness are made by creasing. 
     
     
       5. The method according to  claim 1 , wherein a horizontal edge flange is formed on the upper edge of the sidewalls from a different material than the blank. 
     
     
       6. The method according to  claim 5 , wherein the horizontal edge flange is formed from plastic material. 
     
     
       7. The method according to  claim 1  wherein the at least two discontinuous areas of reduced bending stiffness are provided with a constant width of over 2 mm. 
     
     
       8. The method according to  claim 1  wherein the at least two discontinuous areas of reduced bending stiffness are provided with a constant width between 2.5-4.0 mm. 
     
     
       9. The method according to  claim 1 , wherein the package is provided with four discontinuous areas of reduced bending stiffness. 
     
     
       10. A package comprising a cardboard blank having a bottom and side walls extending upward from the bottom, the blank having straight sides and rounded corners, and at least two discontinuous areas of reduced bending stiffness compared to a bending stiffness of the bottom, the at least two discontinuous areas of reduced bending stiffness being located in a transition zone between the bottom and side walls of the package, wherein the at least two discontinuous areas of reduced bending stiffness are formed as elongated areas that run parallel to the straight sides of the blank and are separated by at least one corner section and wherein the at least one corner section does not have an area of reduced bending stiffness, and wherein the blank is deformed due to moulding. 
     
     
       11. The package according to  claim 10 , wherein the at least two discontinuous areas of reduced bending stiffness are areas of reduced thickness of the blank. 
     
     
       12. The package according to  claim 10 , wherein the at least two discontinuous areas of reduced bending stiffness have a constant width of over 1 mm. 
     
     
       13. The package according to  claim 10 , further comprising a horizontal edge flange formed on the upper edge of the sidewalls from a different material from the blank. 
     
     
       14. The package according to  claim 13 , wherein the horizontal edge flange is formed from plastic material. 
     
     
       15. The package according to  claim 10  wherein the at least two discontinuous areas of reduced bending stiffness have a constant width of over 2 mm. 
     
     
       16. The package according to  claim 10  wherein the at least two discontinuous areas of reduced bending stiffness have a constant width between 2.5-4.0 mm. 
     
     
       17. The package according to  claim 10 , wherein the package comprises four discontinuous areas of reduced bending stiffness. 
     
     
       18. The package of  claim 17  wherein two of the discontinuous areas of reduced bending stiffness are on opposite sides of the bottom in a first direction and two of the discontinuous areas of reduced bending stiffness are on opposite sides of the bottom in a direction perpendicular to the first direction. 
     
     
       19. The package of  claim 17  wherein there are four corner sections, the four corner sections not having an area of reduced bending stiffness, and wherein the four discontinuous areas of reduced bending stiffness are separated by the four corner sections. 
     
     
       20. The package of  claim 10  wherein the at least two discontinuous areas of reduced bending stiffness are on opposite sides of the bottom. 
     
     
       21. A package blank of planar shape made of cardboard, the blank having straight sides and rounded corners, the blank comprising a middle portion and a margin area surrounding the middle portion, wherein the blank comprises at least two discontinuous areas of reduced bending stiffness compared to a bending stiffness of the middle portion, the at least two discontinuous areas of reduced bending stiffness being located around the middle portion of the blank in a transition zone between the middle portion and the margin area, wherein the at least two discontinuous areas of reduced bending stiffness are formed as elongated areas that run parallel to the straight sides of the blank and are separated by at least one corner section and wherein the at least one corner section does not have an area of reduced bending stiffness. 
     
     
       22. The package blank according to  claim 21  wherein the at least two discontinuous areas of reduced bending stiffness have a constant width of over 1 mm. 
     
     
       23. The package blank according to  claim 21  wherein the at least two discontinuous areas of reduced bending stiffness have a constant width of over 2 mm. 
     
     
       24. The package blank according to  claim 21  wherein the at least two discontinuous areas of reduced bending stiffness have a constant width between 2.5-4.0 mm.